Absolute zero: the temperature at which there is no longer any atomic or molecular vibrational motion: -459.67° Fahrenheit, -273.15° Centigrade, and 0° Kelvin. Deep outer space is 3° above absolute zero everywhere due to heat left over from the Big Bang 13.7 billion years ago. This 3° Kelvin background radiation (see "COBE") is the strongest evidence we have that the Big Bang actually took place. Physicists at MIT were able to get within 1/2 of one billionth of a degree of absolute zero in late 2003. Since temperature is a measure of atomic speed, cooling slows atoms down. At room temperature atoms move at the speed of a jet plane. At this new temperature it takes atoms half a minute to move just one inch. This allows physicists to study important tiny atomic movements that are otherwise drowned out in the fast vibrational motion of atoms and molecules at higher temperatures.

Afflicted: a planet in a sign contrary to it’s nature, as Moon in Capricorn or Scorpio; Mars in Libra, Taurus or Cancer; or Venus in Aries, Virgo or Scorpio; OR with a hard aspect from Mars, Saturn, Uranus, Neptune or Pluto. Jupiter afflictions are not as severe, and denote excesses or poor judgment.

Air: one of the four elements (earth, air, fire and water) by which the signs and the houses are categorized. The element of air represents thought, relationship, and the breath. For its application in the signs and houses, see below. To read more about the air element in a Natal Chart, Click here!

Air sign: The element of thought, knowledge, relationship, and all aspects of the mind, as exemplified by the air signs Gemini, Libra and Aquarius. If a liquid is continuously heated, there comes a point at which the average vibrational energy of the constituent particles so exceeds their bonding energy that they repel each other. At this point the liquid boils and becomes a gas - the counterpart of the astrological element air. See "plasma" for an explanation of temperature, absolute zero, and the four states of matter.

Angle(s): the first, fourth, seventh or tenth house cusps, formed from the intersection of the local horizon and meridian circles with the ecliptic. To read more about the twelve houses in a Natal Chart, Click here!

Angular: the first, fourth, seventh or tenth houses, or said of a planet therein; a planet in these houses is very strong, and if conjunct an angle (orb about 3° - 6°) its energy is probably the most projected or noticeable in the chart; the closer to the angle, the stronger this effect is. To read more about the twelve houses in a Natal Chart, Click here!

Aphelion: the point in its orbit where an object is furthest from the Sun (opposite of perihelion); the term apogee is used for objects orbiting the Earth; "apoapsis" is used for the furthest point in orbit around other bodies.

Ascendant (Asc) or Rising Sign: the intersection of the local eastern horizon with the ecliptic; where planets rise or ascend in the east; the beginning or cusp of the first house. That part of our self with which we most identify in our ego; where we project our personality. To read more about the Ascendant or Rising Sign in a Natal Chart, Click here!

Aspect: The angle in the ecliptic plane between two planets with the Earth at the apex of that angle is said to be the "aspect" between those two planets. Planets are said to be "in aspect" when the angle between them is close to 360° divided by 1, 2, 3, 4, 6, 8, or 12. These small divisors are said to be the "harmonic number" of that aspect. This division results in aspects of 360° (=0°: the conjunction, or first harmonic), 180° (the opposition, or second harmonic), 120° or 240° (the trine, or third harmonic), 90° or 270° (the square, or fourth harmonic), 60° or 300° (the sextile, or sixth harmonic), 45° or 135° (the semisquare and sesquiquadrate, both eighth harmonics), and 30° or 150° (the semisextile and quincunx, both twelfth harmonics). Aspects resulting from 360° divided by 5, 7, 9, 10, 11, or integers larger than 12 are less common, but the first two of these, the fifth (the quintile) and the seventh (the septile) harmonics are usually calculated and displayed in your chart.

Planets in aspect combine energies and work in harmony, in discord, or in a more esoteric fashion. Two planets 122° apart, for example, are said to be in "trine" aspect, because they’re close to one third of the circle (120°) apart.

Although the faster of any two planets in aspect is the active force making the aspect, the faster one is always learning lessons from and being shaped by the slower planet, and never vice-versa. In the case of Venus opposed Neptune for example, since Venus is closer to the Sun and therefore faster in its orbit than Neptune, Venus is the one learning lessons from and being shaped by Neptune. The planets from slowest to fastest - from teacher to student - are Pluto, Neptune, Uranus, Saturn, Jupiter, Mars, Sun, Venus, Mercury and the Moon.

AU: short for "astronomical unit:" the distance of the Earth from the Sun, or 93 million miles. The AU is used as a unit of astronomical distance, or measurement, usually between objects in or near the solar system. For example, Jupiter is 5.2 AU from the Sun, and because of its highly elliptical orbit, Pluto varies between 29.6 and 49.6 AU from the Sun. The boundary between the Sun’s influence and interstellar space where the Sun’s solar wind runs into the solar winds of the stars (the heliopause), is 100 AU from the Sun. Comets in highly elliptical orbits can travel as far as 50,000 AU from the Sun. For larger distances, light years or parsecs are used.

Cadent: said of the third, sixth, ninth, and twelfth houses. These houses immediately precede the four angles in a chart, and planets in them are subtler in their expression than in angular houses. Planets in cadent houses are often indicative of mental energy, act in the background, and have an effect on one’s thinking. To read more about the houses in a Natal Chart, Click here!

Cardinal: those signs beginning each season, Aries, Cancer, Libra, and Capricorn. This quadruplicity denotes force manifesting in matter, activity, creativity, crisis, directness, speed and assertion. Planets in different Cardinal signs are often square or opposed, and thus inharmoniously related. To read more about the Cardinal Signs in a Natal Chart, Click here!

Cerberus: a three-headed dog with a snake’s tail and snakeheads protruding from his back, one of the offspring of Typhoeus and Echidna, guarding the only gate into hell. Orpheus was one of the few living mortals to get past Cerberus by charming it to sleep with song during his attempt to rescue Eurydice from death. Hercules’ last labor was bringing Cerberus from the underworld and showing him to King Eurystheus.

Chart: a picture centered around a circle representing the local sky at the time and place in question that astrologers then interpret. The circle is divided into 12 parts in two independent ways: one called the signs, the other the houses. The planets are interpreted by the house they fall in, the sign they occupy, their angular relationships to each other, and their pattern as a whole. To see a picture of the twelve houses including rising sign in a Natal Chart, Click here!

Chiron: a solar system object with the characteristics of both a comet and an asteroid. Discovered in October 1977, Chiron is peculiar because it has a coma - a cloud of water, carbon dioxide and other gases sublimed from its nucleus indicating it is a cometary body – yet is also 75 to 100 miles in diameter, more than 50,000 times the size of a normal comet. This size is characteristic of a large asteroid, which it was first thought to be. Its unusually elliptical orbit from just inside Saturn’s orbit to approximately that of Uranus’ is also unstable over millions of years, indicating that, in astronomical terms, it hasn’t been there very long. This is supported by the fact that Chiron’s coma is still active, yet the super-volatiles (its coma) sublimating from its surface would have completely vaporized in a few million years at its current orbit’s position.

Dozens of bodies have since been discovered with similar orbits and properties. In recognition of their dual comet/asteroid nature they have been designated Centaurs, the mythological Greek race that was half man, half horse. They are hypothesized to be escaped Kuiper belt objects because gravitational perturbations from Jupiter and Saturn would occasionally force Kuiper belt objects into Neptune-crossing orbits that could evolve into orbits like the Centaur’s. The similarity in size between Chiron and other Kuiper belt objects also makes it a likely source. Although asteroids are in this size range too, Chiron’s coma rules out an asteroidal origin.

Chiron, the mythological being, was renowned for his goodness and wisdom. Whereas the other centaurs were rowdy party animals given even to looting and rape, he dedicated himself to the study of medicine, music, astrology and the martial arts. A renowned teacher counting Achilles and Hercules among his many students, he taught the latter how to make the poison-tipped arrows assuring victory in battle. There are many versions of this story, but either he accidentally dropped a poisoned arrow on his own foot, or Hercules accidentally shot him during a fight over some other centaurs’ wine. In either case he became violently ill, but being immortal, was unable to die. He then retreated to his cave to heal himself, and in so doing created the healing arts. Ironically and despite this great achievement, his wound never healed. Chiron, living daily in great pain, elected finally to meet Zeus’ condition and be the immortal to die in Prometheus’ place. (To punish Prometheus for stealing fire and giving it to the mortals, Zeus had chained him to a rock where vultures forever ate his liver.) Chiron may be the centaur in the constellation Centaurus.

Chiron, the wounded healer, symbolizes those who find the strength through suffering to help others avoid the pain they themselves have had to undergo. We are often directed and made wise by own painful childhood experiences. Some astrologers believe that Chiron’s house and sign show where we have been deeply wounded, and may hold the key to our own healing. Chiron teaches us that our wounds contain a gift, and that the process of healing oneself is a journey back to greater wholeness and integrity: the gift of who we truly are. To see what "Chiron" looks like in a Natal Chart, Click here!

COBE: The COBE (Cosmic Background Explorer) satellite was developed by NASA’s Goddard Space Flight Center to measure the diffuse infrared and microwave radiation from the early Universe after the Big Bang. Launched in 1989 it carried three instruments, a Far Infrared Absolute Spectrophotometer (FIRAS) to compare the spectrum of the cosmic microwave background radiation with an ideal absorber and emitter of radiation ("blackbody"), a Differential Microwave Radiometer (DMR) to sensitively map the cosmic radiation, and a Diffuse Infrared Background Experiment (DIRBE) to search for the cosmic infrared background radiation. Each COBE instrument yielded a major cosmological discovery:

FIRAS - The cosmic microwave background (CMB) spectrum is that of a nearly perfect blackbody with a temperature of 2.725° ± 0.002° K. This means that the temperature of outer space is less than 3 degrees above absolute zero in every direction we can see, almost without variation. This observation matches the predictions of the hot Big Bang theory extraordinarily well, and indicates that nearly all of the radiant energy of the Universe was released within the first year after the Big Bang.

DMR - The CMB was found to have intrinsic "anisotropy" (differences dependent upon the direction or place of measurement) for the first time, at a level of a part in 100,000. These tiny variations in the intensity of the CMB over the sky show how matter and energy was distributed when the Universe was still very young. Later, through a process still poorly understood, the early structures seen by DMR developed into galaxies, galaxy clusters, and the large-scale structure that we see in the Universe today.

DIRBE - Infrared absolute sky brightness maps were obtained to carry out a search for the cosmic infrared background (CIB). The CIB represents a "core sample" of the Universe: the cumulative emissions of stars and galaxies dating back to the epoch when these objects first began to form. The COBE CIB measurements constrain models of the cosmological history of star formation and the buildup over time of dust and elements heavier than hydrogen, including those of which living organisms are composed. Dust has played an important role in star formation throughout much of cosmic history.

Comet: a small, fragile, irregularly shaped body composed of ices (water and frozen gases) and dust that was not incorporated into a planet when the solar system was formed. Comets have highly elliptical orbits bringing them very close to the Sun and deep into space, often well beyond the Pluto’s orbit. Only visible near the Sun, comets are thought to reside in the Kuiper belt or the Oort cloud. Most of a comet’s ice and gas is dissipated after a few hundred passes near the Sun. The remaining rocky object appears to be so like an asteroid that as many as half of the near-Earth asteroids may be "dead" comets.

Conjunct: said of two planets (or a planet and an angle) that are less than 8° apart; denotes power or intensity. Most astrologers agree on the 8° orb. To what conjunct looks like in a Natal Chart, Click here!

Constellation: any group of stars in a pattern thought to resemble a deity or object after which it was named. The Sun, Moon and planets all appear to move through only 12 constellations (the zodiac) due to their all lying in the ecliptic plane.

Contraparallel: the aspect between two planets that are the same angular distance north and south of the celestial equator (the Earth’s equator projected onto the celestial sphere) and on opposite sides of it; orb 1°. Two planets with opposite "declinations" are said to be in contraparallel; see "declination" and "parallel." This aspect is said to act like the conjunction when two planets have the same declination and are on the same side of the celestial equator (in parallel), and like the opposition when two planets have the same declination and are on opposite sides of the celestial equator (in contraparallel).

Decanate: three sequential 10-degree sections of all signs: the first 10° of any sign is said to be of the nature of the sign itself; the second 10° decanate is of the nature of the next sign of the same element; and the third has the nature of the remaining sign of that element.

Declination: in the equatorial coordinate system, the angle that an object is above or below the Earth’s equator projected on the celestial sphere. This coordinate corresponds to latitude on the Earth. The other coordinate in this system is called "Right Ascension."

Descendant: The intersection of the ecliptic with the western horizon where planets set or descend; the beginning of the Seventh house. The Descendant in our chart is our experience of others and the world as not-self; lost aspects of our self that we experience through - or look for in - others, and with which we are least identified. To see where the Descendant is in a Natal Chart, Click here!

Detriment: a planet is said to be in its detriment in the sign opposite the one it rules. Here a planet's power is blocked, its full expression hindered, or it has difficulty expressing its positive or optimistic side (in a sign so uncongenial to its nature). A detriment can be too much (overkill) above what is necessary. The Sun is in its detriment in Aquarius, the Moon in Capricorn, Mercury in Sagittarius or Pisces, Venus in Aries or Scorpio, Mars in Libra or Taurus, Jupiter in Gemini, Saturn in Cancer, Uranus in Leo, Neptune in Virgo, and Pluto in Taurus.

Direct: the apparent forward/clockwise motion of a planet against the background stars as seen from the Earth, as opposed to apparent backward ("Retrograde") motion of that same planet seen from the Earth.

Earth: one of the four elements (earth, air, fire and water) by which the signs and the houses are categorized. In general, the element of earth represents matter, material affairs, and al things practical. For its application in the signs and houses, see below. To read more about the earth element in a Natal Chart, Click here!

Earth (sign): The practical, material, physical and solid element exemplified by the earth signs Taurus, Virgo and Capricorn. In a physical solid - the counterpart of the astrological element earth - the bonding energy holding the constituent atoms together is stronger than the atom’s vibrational energy. This is what makes a solid a solid and gives it a fixed geometry. See "plasma" for an explanation of temperature, absolute zero, and the four states of matter. To read more about the earth sun signs in a Natal Chart, Click here!

Ecliptic (Plane): the plane of the Earth’s orbit around the Sun, hence the apparent path of the Sun around the Earth. All of the planets’ orbital planes are inclined less than 3.4° to the ecliptic plane (except Mercury’s at 7° and Pluto’s at 17°). The ecliptic differs from the zodiac in that the former is a plane that has no "thickness" (or "celestial latitude," measured along great circles running perpendicular to the ecliptic and through the ecliptic pole), whereas the zodiac is a band of 12 constellations centered on the ecliptic but also extending north and south of it by 10 - 15°. The Earth’s polar axis is inclined 23.5° to the ecliptic (see page 64), which gives rise to the seasons.

Equinoxes (see Precession): Twice a year a line drawn from the Sun to the Earth falls on the Earth’s equator. Experienced on Earth as the moment the Sun crosses the equator, on that day all over the Earth day and night are of equal length. Hence the Latin equinox (equal night). In spring this moment, around March 21st, is called the vernal equinox,‘. It defines 0° of the sign Aries and marks the beginning of the astrological year and the annual cycle of light and dark. From its low at the winter solstice š, the light force waxes through the vernal equinox ‘ to its maximum at the summer solstice ". Thence it wanes through its balance point at the autumnal equinox — back to its nadir at the winter solstice š.

The "signs" are 12 equal divisions of the interval between successive vernal equinoxes that slowly move* relative to the fixed stars. "Tropical" astrologers believe that the 12 signs are interpretively significant. "Sidereal" astrologers believe that the fixed groups of stars (constellations) from which the signs originally took their names are interpretively significant. *Since the Earth is not a perfect sphere (see "oblateness"), the Sun and Moon pull on it unevenly.

This non-uniform pull or force causes the Earth’s spin axis to wobble or "precess" in space, the way a top’s axis pulled on by gravity circles the vertical as it slows down. Thus the Earth’s equator and its line of intersection with the ecliptic precess as well. Since this line of intersection is the line of the equinoxes, we get the "precession of the equinoxes." This wobble takes 25,788 years to complete one cycle, or 2150 (25,788÷12) years/sign. A "great age" takes its name from the group of stars (constellation) through which the vernal equinox is currently precessing. Thus the Age of Pisces lasted from about the birth of Christ to the mid-20th century, and the Age of Aquarius will last from the mid-20th century until about 4100 AD.

Exact: said of an aspect whose orb is 0°. For example, a trine of 123° has an orb of 3°, whereas a trine of 120° is exact. Aspects are rarely exact, but rather approach being exact as their limiting, strongest, or most compelling condition. To read more about aspects in a Natal Chart, Click here!

Exalted: said of a planet in its strongest, most creative sign placement: the sign of its Exaltation. Here it can express its energy in its highest, most positive form. The Sun is Exalted in Aries, the Moon in Taurus, Mercury in Aquarius, Venus in Pisces, Mars in Capricorn, Jupiter in Cancer, and Saturn in Libra. Exaltation is not particularly significant for the outer planets.

Fall: said of a planet in the sign opposite to its Exaltation; the weakest and least favorable placement for a planet, resulting in a restriction of its nature and an inability to express its positive or optimistic qualities. This is personally significant only for Moon in Scorpio, Mercury in Leo, Venus in Virgo, Mars in Cancer; and, to a lesser extent, Jupiter in Capricorn and Saturn in Aries.

Feminine (Yin): receptive water or earth qualities or signs. Taurus, Cancer, Virgo, Scorpio, Capricorn and Pisces are the feminine, Yin signs. To read more about the elements of water and earth in a Natal Chart, Click here!

Finger of God ("Yod"): A triangular aspect structure with one planet at the vertex of the triangle in quincunx to two other planets in sextile to each other. The whole structure points to the planet at the apex: a special task in life beneficial to one’s evolution. Thought to be a fateful, constant, and relatively unchanging condition. To see what the Finger of God or "Yod" in a Natal Chart looks like, Click here!

Fire: one of the four elements (earth, air, fire and water) by which the signs and houses are categorized. The element of fire represents energy, enthusiasm, inspiration, and the spirit. For its application in the signs and houses, see below. To read more about the fire element in a Natal Chart, Click here!

Fire house: the first, fifth, and ninth houses; those houses that have the same ordinal numbers as the three fire signs. Isabelle Hickey called the fire house trinity the "Trinity of Life," with the first house being the house of the body, the fifth the house of the soul, and the ninth the house of the spirit. These houses partake in the qualities of the fire signs, particularly if their occupants are trined or all linked in a Grand Trine. To read more about the houses in a Natal Chart, Click here!

Fire sign: The element representing inspiration, energy, enthusiasm, being forceful, impulsive, and joie de vivre - exemplified by the fire signs Aries, Leo and Sagittarius. The physical equivalent of the astrological element fire is plasma, a gas that has lost some or all of its electrons by being heated or electrically excited. All stars are composed of plasma. The four states of matter (solid, liquid, gas, plasma) differ only in the relative degree at which their atoms vibrate. See "plasma" for an explanation of temperature, absolute zero, and the four states of matter. To read more about Aries, Leo or Sagittarius in a Natal Chart, Click here!

Fixed: the second or middle sign of a season, denoting will, power, stability, and stubborn or inflexible energy. Taurus, Leo, Scorpio, and Aquarius. To read more about a fixed sign in a Natal Chart, Click here!

Grand Cross: four planets in square aspect, including 2 oppositions (a complete fourth harmonic syndrome). This is an intense and often stressful structure needing a focus for it’s considerable energy into specific purposes and constructive action. Usually a grand cross occurs all in one quadruplicity: if in Cardinal signs, the outlet for the energy is action; in Fixed signs, the outlet is emotional and/or surrendering self-will; in Mutable signs, being able to see all sides leads to indecisiveness and diffusion of energy: an adjustment in thinking habits is necessary. To see what a Grand Cross looks like in a Natal Chart, Click here!

Grand Trine: three planets each in trine to the other two; a complete third harmonic syndrome; perfect equilibrium and balance denoting great talent, ease or harmony, usually all in one element (earth, air, fire, or water); often a static, passive, inert structure not promoting the growth that confronting the problems of the hard aspects does - for this reason the ancients used to think of the Grand Trine as evil or malefic. To see what a Grand Trine looks like in a Natal Chart, Click here!

Gyroscope: invented in 1852 by the French experimental physicist Leon Foucault (1819-1868) as part of a two-pronged investigation of the rotation of the earth. The better-known demonstration of the Foucault pendulum showed that the plane of rotation of a freely swinging pendulum rotated with a period that depends on the latitude of its location. His gyroscope was a rapidly rotating disk with a heavy rim, mounted in low-friction gimbals. As the earth rotated beneath the gyroscope, it would maintain its orientation in space. This proved to be hard to do in practice because frictional forces brought the system to rest before the effect could be observed.

Harmonic: If an aspect is expressed as a fraction of 360°, the denominator of that fraction is the harmonic number of the aspect. Each of the following aspects is followed by its harmonic number: opposition-2, trine-3, square-4, sextile-6, septile-7, semisquare-8, sesquiquadrate-8, semisextile-12, quincunx-12.

Harmonic Syndrome: three or more planets mutually in an aspect pattern of the same harmonic, like the grand Trine, the T-square, the Grand Cross, the Yod, the Grand Hexagram, or five planets each in septile to each other. To see what a Grand Trine looks like in a Natal Chart, Click here! To see what a T-Square looks like in a Natal Chart, Click here! To see what a Grand Cross looks like in a Natal Chart, Click here! To see what a Yod looks like in a Natal Chart, Click here! I do not yet have a Grand Hexagram posted on this website.

Heliopause: The boundary marking the end of the Sun’s influence and separating our solar system from interstellar space, where the expanding solar wind from our Sun eventually runs into the solar winds of other stars (the interstellar medium). It is thought to be about 10 billion miles - three time Pluto’s distance - from the Sun.

Higher Octave: the relationships of the three outer planets to the three inner planets: Uranus (lightning-fast intuition) is the higher octave of Mercury (rational thought); Neptune (divine compassion) is the higher octave of Venus (personal love); and Pluto (evolution, transformation) is the higher octave of Mars (libido and ego drive). To read more about planetary glyphs in a Natal Chart, Click here!

Hipparchus of Rhodes: (190 - 120 BC) was probably the inventor of trigonometry, the first person to suggest that the earth rotated on its axis, the first to obtain a measurement of the earth’s diameter, calculated the distance to the Moon (between 59 and 67 earth radii, 60 earth radii is correct), calculated the length of the year to within 6.5 minutes, discovered the precession of the equinoxes (46" of arc compared to the modern 50.26", and much better than the 36" that Ptolemy obtained 300 years later), was the first known person to appreciate the vast distance to the stars, created a star catalogue of about 850 stars, and introduced the division of the circle into 360 degrees into Greece.

House (System): any of over 9 different systems of dividing the ecliptic into 12 interpretive sections, or houses, named after the monks and others who developed them, namely Placidus, Koch, Ptolemy, Porphyry, Campanus, Regiomontanus, Alcabitius, Morinus and Zariel. Due to an historic serendipity in its publishing, Placidus is the most popular. House systems either divide up the ecliptic, divide up the quadrants between the angles, or divide up the time. I use the Placidus House System when calculating charts.

I.C. or Imum Coeli: "Imum Coeli" or "lowest heaven"; the fourth house cusp. The most intimate and personal point in the chart: one’s innermost feelings, roots, and internal sense of one’s self. To see what "Imum Coeli" looks like in a Natal Chart, Click here!

Inconjunct: originally applied to both the semisextile (30°) and the quincunx (150°) by Ptolemy and other Greeks; now refers to the quincunx only. To see what the "Inconjunct" looks like in a Natal Chart, Click here!

Interstellar: referring to the space between the stars. The expanding solar wind from our Sun eventually runs into the solar winds of other stars at a boundary marking the end of the Sun’s influence (and separating our solar system from interstellar space) known as the "heliopause." Thought to be about 10 billion miles - three time Pluto’s distance - from the Sun, the heliopause may soon be reached by the Voyagers 1 and 2 launched back in 1977. The Oort cloud may also mark the physical end of our solar system and the beginning of interstellar space.

Kelvin: the absolute scale of temperature, which begins at the point at which there is no atomic or molecular motion known as "absolute zero." This is 459° below 0 on the Fahrenheit scale, and is the definition of 0° on the Kelvin scale. See "plasma" for an explanation of temperature, absolute zero, and the four states of matter.

Kuiper Belt: a disk-shaped region of many small icy bodies extending from just beyond Neptune’s orbit to about three times further out from the Sun. It’s estimated to contain more than 35,000 objects greater than 60 miles in diameter (several hundred times the number of similar-sized objects in the asteroid belt), and as many as 100 million comets 12 or so miles across. Pluto is thought to be a Kuiper belt object and not a true planet because of its small size and the extreme inclination and ellipticity of its orbit.

Light Year: the distance light travels in one year; at the speed of 186,282 miles/second, this amounts to a distance of 5.88 trillion miles. Notice that a light year is a unit of distance, not of time. The nearest star is 4.4 light years away, and our own galaxy, the Milky Way, is a spiral of 200 billion stars that is 10,000 light years thick at its central bulge and 100,000 light years in diameter. The nearest galaxy to us, the Andromeda galaxy, is 2.3 million light years away, and the entire Universe is thought to be about 27.4 billion light years in diameter.

Magnitude: numbers assigned to heavenly bodies indicating their relative brightness: the smaller the number, the brighter the object. Thus the brightest star, Sirius, with a magnitude of -1.44, is brighter than a star of magnitude 0, which in turn is brighter than a star of magnitude 1, etc. The faintest object the human eye can see is magnitude 6, about the brightness of the planet Uranus.

The Hubble Space Telescope can see some faint galaxies as dim as the 30th magnitude, 4 billion times fainter than the faintest object the human eye can see. In general, objects are 2.512 times brighter than objects one magnitude less. Thus, a first magnitude star is 2.5x2.5.x2.5x2.5x2.5 = 100 times brighter than a star of magnitude 6. Venus, the brightest object in the sky other than the Sun or Moon, has a magnitude of -4.4. The full Moon’s magnitude is -12.7, and the Sun’s magnitude is -26.75.

Major Aspect: the conjunction, opposition, trine, square and sextile aspects; those aspects having angular separations of 360° divided by 1, 2, 3, 4 or 6, that is, with harmonic numbers of 1, 2, 3, 4 or 6. To see what the aspects look like in a Natal Chart, Click here!

Mass: An object's weight (not its mass) is a measure of how much the planet Earth pulls on that object. Hold an object in your hand. You can feel the Earth pulling it. But that feel of weight is a result of an interaction between the Earth and the object. Newton established that all bodies in the universe attract each other with a force that increases as mass of the bodies increases. Thus an object's weight depends on two things: how much stuff is in the object itself, and much stuff is in the object pulling on it, in this case, the Earth. It follows that an object's weight is greater in the gravitational field of the Sun, and less in the gravitational field of the moon.

Newton realized that all objects have an intrinsic property that doesn't depend on the planet pulling on the object, a property that stays the same whether or not the object is on the Sun, the Moon, or on the Earth. This intrinsic property of any body, independent of where it is in the universe, is called the body's mass. And a body's mass can be obtained by taking its weight -- which depends on how much a particular "planet" is pulling on it to make it "heavy" -- and dividing its weight by the strength of the particular planet's pull on it.

Now Newton discovered that the Earth pulls on (or accelerates) all objects with the same amount of force. This is the gist of his apocryphal falling apple experience. If you were to drop 1 pound of feathers and a 1-pound lead ball from the same height in a vacuum, they would both hit the ground at the same time. Why "in a vacuum?" Because air resistance would impede the falling feathers more than the falling lead ball -- but they are both being pulled on (or accelerated by) the Earth with one pound of force, which is experienced on the Earth as their weight.

Since the Earth's pull is a constant for all bodies, it can be easily calculated. It is 32 feet/9.8 meters per second per second. The "per second per second" is because acceleration is a change in velocity, so the Earth's pull increases a falling body's velocity 32 feet per second every second. Thus the Earth's constant pull on all objects can be divided out of the weight of any object. And when you divide an object's weight by the pull of the body in whose gravitational field you're measuring its weight (like the Earth's pull), you're left with its "mass" (the units of which are "slugs" in the English system).

Thus a body's mass is independent of the planet in whose gravitational field you're weighing it. So although its weight differs on Mercury, the Sun, the Moon and Jupiter, its mass remains constant on all those bodies. Mass is the amount of stuff a body has in it, not how hard a particular body or planet is pulling on that stuff -- which is its weight.

MC (Medium Coeli): Latin for "middle of the sky"; the intersection of the local meridian with the ecliptic; the Midheaven, or tenth house cusp. To see where the Medium Coeli a.k.a. Midheaven is in a Natal Chart, Click here!

Meridian: any circle with its center at the Earth’s center passing through the observer’s zenith and the North or South Pole. The meridian is that "vertical circle" passing through the center of the Earth and perpendicular to the horizon (the definition of a vertical circle) that also passes through the north and south points on the horizon. The Meridian is also perpendicular to the Prime Vertical, the vertical circle passing through the east and west points on the horizon. The horizon and Meridian planes quarter the local sky and form the 12 houses when trisected by planes perpendicular to the Prime Vertical and passing through the horizon’s north - south line (see diagram on page 117). All local meridians intersect the ecliptic at the tenth and fourth house cusps. The 24 Standard Time Meridians are each 15° apart, and define the time within the irregularly shaped Time Zones around each of them.

Midheaven: The highest point in the local sky on the planet’s path, it is also known as the tenth house cusp, or the Medium Coeli (MC). It is one’s point of maximum externalization: the social world most distant from intimate, personal life. It is what we need to do with our life in order to grow. The midheaven is the ecliptic degree most directly overhead: the intersection of the local meridian with the ecliptic above the horizon. To see where the Medium Coeli a.k.a. Midheaven is in a Natal Chart, Click here!

Minor Aspect: the semisquare, quincunx, semisextile, sesquiquadrate, quintile, biquintile, septile, biseptile, triseptile, novile and decile. To see what the aspects look like in a Natal Chart, Click here!

Minute (‘): the 60 equal divisions of a degree of arc. In a chart, the digits before the little sign symbol accompany the planetary glyphs show the position of each planet in the sign by degrees. The digits after the little sign symbol refine that position to 60ths of a degree, or minutes of arc.

Mutual Reception: the condition where two planets are each located in a sign ruled by the other. This is a beneficial condition, lending harmony and stability to each, and compensates for the detrimental signification otherwise occurring if either or both planets are in its detriment or fall.

Mutable: the third and last sign in each season, associated with flexibility and versatility. Gemini, Virgo, Sagittarius, and Pisces. A lot of Mutable energy in a chart indicates suggestibility, flexibility, and potentially a lack of stability. To see read about the mutable signs in a Natal Chart, Click here!

Nadir: The nadir is the ecliptic degree most directly below, or, the intersection point of the local meridian with the ecliptic below the horizon. The lowest point in the local sky on the path of the planets, it is also known as the cusp of the Fourth house, or imum coeli (I.C.). The nadir is most intimate and personal point in the chart, symbolizing one’s most inner feelings, roots, and internal sense of self.

Natal Chart: A natal chart is an astrological map that is specifically tailored to an individual's birth time, birth date and birth location, which gives insight to a person's mission, purpose, personality, traits, gifts and potentials.

Natural (house) Ruler: the planetary ruler of the sign corresponding to the number of the house in question (e.g., the Sun rules Leo, the fifth sign, and is therefore the natural ruler of the fifth house).

Node(s), Dragon’s Head/Tail: points of intersection of a planet’s orbit with the ecliptic. Usually only the Moon’s nodes are interpreted. The Moon’s South Node (cup holding water) denotes talents, or habit patterns from past lives: that which we know well. The Moon’s North Node is that with which we are least familiar: important new elements we need to add to our lives to grow and to become whole. Comfortable familiarity at the South Node pulls us away from the North Node, making growing there more difficult. To see what the North and South Node look like in a Natal Chart, Click here!

Oblateness: how much a planet has been flattened at its poles by its rotational speed. If the Earth’s size and rigidity were proportionately reduced, it would be similar to a basketball of butter. Now for all spinning balls, the part furthest from the spin axis spins the fastest, like the person at the end in crack the whip. And since the parts of a planet at its equator are furthest from its pole (which is its spin axis), it follows that a planet’s equatorial part has the greatest tendency to fly away. Thus all spinning heavenly bodies are wider through their equators (their "equatorial diameter") than through their poles (their "polar diameter"). This effect increases as a planet spins faster, and decreases the denser the planet is.

The Earth, with a density of 5.5 g/cm3, has an equatorial diameter 27 miles greater than its polar diameter, or an oblateness of 0.3%. Saturn, a gas giant that would float in water with a density of only 0.687 gm/cm3 (the density of water is 1 gm/cm3 ), is 8078 miles thicker through its equator than through its poles. Its oblateness is 10%. If a planet’s equatorial diameter is De and its polar diameter is Dp, then its oblateness is defined as (De - Dp)/De.

On the (house) cusp: when a house cusp falls within a sign, that sign is said to be on (or to "fall" on) the cusp of that house. That sign and its ruling planet are then said to rule the affairs of that house.

Oort cloud: A Dutch astronomer, Jan Oort, observed in 1950 that no comet had ever been seen with an orbit indicating that it came from interstellar space, nor did comets seem to have a preferred direction of origin. He therefore hypothesized that the Sun is surrounded by an immense cloud of comets - the Oort Cloud - extending from about 1200 times Pluto’s distance from the Sun out to about 3 light years.

The nearest star, Proxima Centauri, is 4.25 light years away. So distant that its members are only weakly bound to the Sun, the Oort Cloud is occasionally disturbed by passing stars that fling bits of it either into the inner solar system as comets or out into interstellar space. The Oort Cloud is thought to contain as many as a trillion comets, but since they are so small and at such a great distance, there is no direct evidence that it actually exists at all.

Opposition: the 180° aspect (orb 10°-12°) denoting change, polarity, awareness, objectivity, and often a particular way or style of relating. This is the second strongest aspect and symbolizes a conflict between an internal energy (initially not seen as internal), and an apparently external one (that one fails to see in oneself, and, like the Seventh house, projects onto the outer world). The opposition signifies others we bring into our life to externalize unconscious or rejected aspects of our own being. Accepting these is the growth in consciousness the conflict provides. To see what "Opposition" look like in a Natal Chart, Click here!

Orb: the greatest deviation that an aspect can have from being exact and still be in effect. Orbs are highest for the Sun and Moon, smaller for the inner planets, and smallest for the outer planets. Orbs decrease as the aspect’s harmonic number increases. Most astrologers agree the highest degree to still be effective is 8°.

Outer Planets: Uranus, Neptune, and Pluto. Since they remain 7, 14 and 12 - 33 years respectively in a sign, their effect by sign is generational, collective, and social, rather than individual. The effects of these planets by house, however, are very individual, particularly in the Angular houses. (Pluto stays 12 to 33 years in a sign because its orbit is so highly elliptical.) To see what the planets look like in a Natal Chart, Click here!

Parallax: the apparent shifting of a closer celestial body (a planet or nearby star) against the background of far more distant stars caused by changing one’s point of view. If the two points of view are on opposite sides of the Earth, it is called a "geocentric" or "diurnal" parallax; if on opposite sides of the Earth’s orbit, it is called "heliocentric" or "annual" parallax. Since the distance between those points is precisely known (the diameter of the Earth or its orbit around the Sun), and the angle of shift can be measured, the distance to the closer body can be determined by trigonometry. Parallax is 1/2 of the angle of the aforementioned apparent shift.

In 1672 Giovanni Cassini used a parallax base line from Paris to Cayenne, French Guiana to measure the distance to Mars, and in so doing measured the Earth-Sun distance (1 AU) for the first time. It wasn’t until 1835, however, that the first accurate measurement of a star’s parallax was obtained by Friedrich Bessel for the star 61 Cygni. With a parallax of 0.32 arc-seconds (1/7200th of a degree), its parallax was more than 100 times below the threshold of Tycho Brahe’s ability to measure the position of stars.

Parallel: the aspect between two planets that are the same angular distance north or south of the celestial equator ( the Earth’s equator projected onto the celestial sphere) and are on the same side of it; orb 1°. Two planets with the same "declination" are said to be in parallel; see "declination" and "contraparallel." This aspect is said to act like the conjunction when two planets have the same declination and are on the same side of the celestial equator (in parallel), and like the opposition when two planets have the same declination and are on opposite sides of the celestial equator (in contraparallel).

Parsec: 3.26 light years = 19.2 trillion miles. A parsec is defined as the distance to a body with a heliocentric parallax of one second, hence "par - sec" = parallactic second. If a body appears to shift one second of arc against background stars when viewed from opposite points in the Earth’s orbit (182 days apart), its distance from the Earth is one parsec. The nearest star other than the Sun, Alpha Centauri C (Proxima Centauri) is 1.3 Parsecs or 4.22 light years distant.

Part of Fortune (Pars Fortuna): if the Sun were moved onto the Ascendant and the angle between the Sun and the Moon were left unchanged, the Moon’s new position is the Part of Fortune. It denotes success in worldly affairs. To see what the Part of Fortune looks like in a Natal Chart, Click here!

Perihelion: the point in its orbit where an object is closest to the Sun (opposite of aphelion); the term perigee is used for objects orbiting the Earth; "periapsis" is used for the closest point in orbit around other bodies.

Personal Planets: the Sun, Moon, Mercury, Venus and Mars. These planets change positions fast enough to distinguish birth charts close in time from one another. They are also personal in that they relate to an individual rather than to collective or social energy, as do the outer planets. To see what the planets look like in a Natal Chart, Click here!

Plasma: atoms in the gaseous state that have lost some or all of their electrons, usually by being heated or electrically excited. Stars are entirely composed of plasma, akin to the astrological element fire. The four states of matter (solid, liquid, gas, plasma) differ only in the degree to which their atoms vibrate.

The measure of the average vibrational motion of the atoms or molecules of a substance is called its temperature. Thus the lowest temperature possible is when there is no atomic vibration at all. This is called absolute zero: 459 degrees below zero on the Fahrenheit scale, and the beginning - zero degrees - of the Kelvin scale of temperature. Curiously enough, the universe has a very low and uniform temperature in all directions. Known as the "3 degree Kelvin background radiation," this 3° temperature everywhere in outer space is an afterglow of the Big Bang cooled to almost nothing after 13.7 billion years, and the strongest evidence we have that a Big Bang occurred at all.

In a solid - the counterpart of the astrological element earth - the energy holding the constituent atoms together – their "bonding energy" - is stronger than the atom’s vibrational energy. This is what makes a solid a solid and gives it a fixed geometry. As a solid is heated, a point is reached at which the average vibrational energy of its constituent atoms equals or exceeds the energy holding them together. At this point the solid melts and becomes a liquid. A liquid is that state of matter - the counterpart of the astrological element water - in which the average vibrational energy of the constituent particles exceeds their bonding energy. If a liquid is continuously heated, there comes a point at which the average vibrational energy of the constituent particles so exceeds their bonding energy that they repel each other. At this point the liquid boils and becomes a gas - the counterpart of the astrological element air.

If the gas is heated even more, the vibrational energy of its constituent particles eventually becomes so great that its atoms begin to permanently kick off their outer electrons. A gas having lost some or all of its outer electrons is said to be ionized, and is know as a plasma - the counterpart of the astrological element fire.

Precess: A spinning body to which an outside force is applied will tend to rotate in a direction perpendicular to both the outside force and to its spin axis. This resultant rotation is called precession, a movement seen both in spinning tops and in planets.

Precession of Equinoxes: Since the Earth is not a perfect sphere (see "oblateness"), the Sun and Moon pull on it unevenly. This non-uniform pull or force causes the Earth’s spin axis to wobble or "precess" in space, the way a top’s axis pulled on by gravity circles the vertical as it slows down. Thus the Earth’s equator and its line of intersection with the ecliptic precess as well. Since this line of intersection is the line of the equinoxes, we get the "precession of the equinoxes." This wobble takes 25,788 years to complete one cycle, or 2150 (25,788÷12) years/sign. A "great age" takes its name from the group of stars (constellation) through which the vernal equinox is currently precessing. Thus the Age of Pisces lasted from about the birth of Christ to the mid-20th century, and the Age of Aquarius will last from the mid-20th century until about 4100.

Prime Vertical: the "vertical circle" passing through the center of the Earth and perpendicular to the horizon (the definition of a vertical circle) that passes through the east and west points on the horizon. The Prime Vertical is also perpendicular to the Meridian: the vertical circle passing through the north and south points on the horizon. The horizon and Meridian planes quarter the local sky, and form the 12 houses when trisected by planes perpendicular to the Prime Vertical and passing through the horizon’s north - south line.

Progressed: planetary positions (or a whole chart) computed on the principle that one rotation of the Earth on it’s axis (one day) symbolizes one revolution of the Earth around the Sun (one year); said to signify inner development; distinct from transits said to represent exterior events.

Ptolemy, Claudius: (87 to 150 AD), a Greek living in Alexandria, Egypt, codified the Greek geocentric view of the universe in his 12-volume The Almagest (The Greatest). Aristotle and Ptolemy’s perfect geocentric universe became the model for astronomers, astrologers, and, albeit pagan, for the Christian church for 2000 years.

Pythagoras: Nothing of Pythagoras’ writings has survived. His half religious, half scientific society followed a code of secrecy that has left him a mysterious figure. Early biographers attributed divine powers to Pythagoras and presented him as a god-like figure. Nevertheless, we know his primary teachings were that: reality, at its deepest level, is mathematical in nature; philosophy can be used for spiritual purification; the soul can rise to union with the divine; and that certain symbols have a mystical significance.

Quadruplicity: three groupings of the signs by the category of force they typify (or their seasonal position). They are: Cardinal (dynamic, active), Fixed (latent, stable), and Mutable (harmonizing, flexible). Planets in the same quadruplicity are square or opposed, and in tension with each other. To read more about "Quadruplicity" in a Natal Chart, Click here!

Quincunx: the 150° aspect; the inconjunct. It unites signs with no natural relationship or connection: discord, necessity for adjustment, or a forced choice between inharmonious conditions; orb 1.5° - 2°. To see what a "Quincunx" looks like in a Natal Chart, Click here!

Retrograde: the "apparent" backward motion of a planet against background stars as seen from Earth. Someone with retrograde planets is redoing those planets’ functions in a highly personal, individualistic sense. Things manifest more slowly for a retrograde planet; one is more subjective and thinking more deeply about it. The retrogradations of Mars, Venus, and Mercury, in that order, are the most significant. The retrogradations the outer planets, Uranus, Neptune and Pluto are not as personally significant because they are retrograde about half the time. To read what each planet means in retrograde motion in a Natal Chart, Click here!

Right Ascension: the arc on the celestial equator extending eastward from the vernal equinox to the meridian of the object in question in the equatorial coordinate system. This coordinate corresponds to longitude on the Earth. The other coordinate in this system is called "declination."

Rising (sign): In natal astrology, the sign on the Ascendant (first house cusp). In horary astrology, the sign rising in the east at the time in question. To see what a Rising Sign is in a Natal Chart, Click here!

Ruler (of the Chart): the planet ruling the rising sign (Ascendant) is said to be the Ruler of the chart. Thus if you have Cancer (or Gemini) rising, the Moon (or Mercury) is the ruler of your chart. To see what a Rising Sign is in a Natal Chart, Click here!

Ruler (sign): A planet is said to rule that sign which typifies or characterizes its energy, and in which it expresses itself most freely and naturally. A planet is said to be "dignified" in the sign it rules. The Sun rules Leo; the Moon, Cancer; Mercury, Gemini and Virgo; Venus, Taurus and Libra; Mars, Aries and Scorpio; Jupiter, Sagittarius and Pisces; Saturn, Capricorn and Aquarius; Uranus, Aquarius; Neptune, Pisces; and Pluto, Scorpio. Aquarius, Pisces, and Scorpio were ruled by Saturn, Jupiter, and Mars until their rulers Uranus, Neptune, and Pluto were discovered. To see what each planet rules in a Natal Chart, Click here!

Semisextile: an aspect of 30°, or 1/12th of the circle. It unites signs with no natural relationship or connection. The semisextile indicates discord, necessity for adjustment, and/or a forced choice between two inharmonious conditions. Some astrologers attribute Second house qualities of resources and values to it; orb 1.5° - 2°. To see what a "Semisextile" looks like in a Natal Chart, Click here!

Semisquare: the 45° aspect, or 1/8th of the circle. It denotes tension, or a planetary function in the service of collective forces; orb 2° - 2.5°. To see what a "Semisquare" looks like in a Natal Chart, Click here!

Sesquiquadrate: a 135° aspect the semisquare or 8th harmonic family; 3/8th or 5/8th of the circle; crisis, resistance to challenge; orb 2° - 2.5°. To see what a "Sesquiquadrate" looks like in a Natal Chart, Click here!

Sextile: a 60° aspect; or 1/6th of the circle, denoting opportunity. Unlike the trine, the sextile needs a little push from the individual’s will to activate the natural harmony of this aspect; orb 4° - 5°. To see what a "Sextile" looks like in a Natal Chart, Click here!

Sidereal: "of the stars;" said of astrologers who believe that the constellations rather than the signs are interpretively significant. Tropical astrologers believe the signs to be 12 equal divisions of the interval between successive vernal equinoxes, and that these 12 stages in the Earth’s light and dark cycle, not the constellations from which they derived their names, are interpretively significant.

Sign: the type of energy a planet has at its disposal, or needs, for proper functioning. Signs qualify or color the energy of the planet(s) in them, and may show how the individual has used or misused that planetary function in past lives. Wise past use shows up as dignified planets or compatible sign placement. Past misuse may be indicated by planets in detriment or fall, incompatible sign placement, or difficult aspects.

Astronomically, a sign is any of 12 equal divisions in the ecliptic, beginning when the Earth’s equatorial plane intersects the Sun marking the beginning of (northern hemispheric) spring, and at a point where a line drawn at that moment from the center of the Earth through the center of the Sun intersects the ecliptic. Since this definition contains a "when," the signs are not fixed in space as are the zodiacal constellations.

Astrologically speaking, a sign is any of the 12 stages in the seasonal light and dark cycle, beginning about March 21st with the Vernal Equinox, which defines 0° of Aries. During the first sign, Aries, light gains ascendancy over dark as day becomes longer than night. Around 0 A.D., not only was the Sun at 0° of the sign Aries (as it always is when the Vernal Equinox occurs), but it was also at the beginning of the constellation (fixed group of stars) Aries. Due to the precession of the equinoxes, however, the signs have moved out of synch with the constellations bearing their names. The signs may have picked up the attributes (and hence the names) of the constellations with which they were coincident between about 2000 B.C. and the birth of Christ. Tropical astrologers regard the signs as interpretively significant. Sidereal astrologers regard the constellations as interpretively significant.

Solar Chart: this is an astrological chart drawn up with the Sun on the cusp of the first house. It is used when there is no birth time. This type of chart is also used in writing horoscopes since astrologers do not know every single person under one Sun Sign's birth information. So the Sun (Sun Sign) is put on the 1st house cusp and then the rest of the signs follow in order around the chart wheel. Sun Sign horoscopes are written with a Solar Chart with the predictions based on transiting planets affecting the solar houses. Astrologers have to set the wheel with your Sun sign at the horizon (1st house cusp aka Ascendant). Then general predictions are made based on the planets' placement in those houses. Again, as far as horoscopes go, the Solar Chart is used since it would be impossible to know every single person under one Sun Sign's birth time, date and location.

Solar wind: a stream of electrically charged particles emitted by the Sun. Flowing continuously outward at a million miles an hour, it causes comets’ tails to always point away from the Sun, disturbs the paths of spacecraft, and causes radio interference, the aurora borealis, and power line surges here on Earth. As it expands out into space, the solar wind creates a magnetic bubble of hot plasma around the Sun called the heliosphere. It defines the limit of the Sun’s influence and, together with the Oort cloud, the limit of our solar system.

Spectral type: All objects in the universe radiate energy in the form of fluctuating electric and magnetic fields. One characteristic of this electromagnetic (EM) radiation is its wavelength. A body’s total radiation can be separated into its component wavelengths by passing it through a prism or a set of microscopic, parallel lines ruled very closely together on transparent material (a "diffraction grating.") The entire collection of wavelengths that a body radiates - as well as their dispersion into component wavelengths by a prism or a diffraction grating - is called that body’s "spectrum" (pl., spectra).

From longest to shortest wavelengths, the entire electromagnetic spectrum consists of radio waves, microwaves, infrared (heat), visible light, ultraviolet light (the shortest visible light), x-rays, gamma rays, and finally cosmic rays. The latter three pass through solids, their penetration increasing as their wavelength decreases. Stars radiate all wavelengths, visible light being just a tiny fraction of their entire EM spectra.

If an object is warm enough, it radiates in the part of the spectrum humans can see known as visible light. It turns out that incandescent solids and gases under high pressure radiate all visible wavelengths, known as a "continuous spectrum." The cores of stars are gases under immense pressure that emit just such continuous spectra of light, the white light from our Sun being an example.

The continuous emission spectrum from a star’s core is selectively absorbed on its journey to us by elements in both that star’s and our own atmosphere. The particular wavelengths absorbed are characteristic of the absorbing element and of its temperature. The resultant "absorption spectrum" is a continuous rainbow with dark lines or gaps in it where those particular wavelengths were absorbed. These absorption lines describe a star’s temperature, the makeup of its atmosphere, and, by any displacement of a line from the wavelength exactly characteristic of its absorbing element, the star’s velocity relative to us (its Doppler shift). Over 25,000 lines are known that correspond to elements in stars.

Stars can be categorized by these spectral signatures characteristic of their surface temperature and directly related to their color. From hottest to coolest, stars’ spectral types and associated colors are O and B (blue), type A (white), type F (yellow-white), type G like the Sun (yellow), K (orange), and M (red).

Square: the 90° aspect, or 1/4 of the circle; obstacles and dynamic inner tension leading to conflict and change. Planets in square work at cross-purposes and resist, test and limit each other. Their energies are released when the aspect is resolved. It’s harder to be aware of or objectify the source of the tension with the square than with the opposition. Planets in square are usually Cardinal, Fixed, or Mutable; orb 6.5° - 7.5°. To see what a "Square" looks like in a Natal Chart, Click here!

Stellium: at least four planets in the same sign, or within a 10° orb if in different signs. The occupied house and/or sign contains a tremendous intensity and complexity of energies represented by the planets involved.

Succedent: said of the houses following the angular houses, namely the second, fifth, eighth and eleventh houses. Planets in succedent houses are thought to be associated with the one’s emotional and desire nature. To see what a where the succedent houses are in a Natal Chart, Click here!

Titans: Gaia, Uranus, and their children: Kronos, Rhea, Oceanus, Tethys, Hyperion, Mnemosyne, Themis, Iapetus, Coeus, Crius, Phoebe, Thea, Prometheus, Epimetheus, Atlas and Metis. The Golden age of Man took place during the rule of Kronos and the Titans. The elder race, or first gods, they refused to give up power to the next generation of gods. A ten-year war ensued between the Titans and the Olympians led by Zeus, resulting in the Titans being exiled to Tartarus, a stormy pit beneath the Earth later called Hades. At the end of the Age of Heroes Zeus released the Titans, making Kronos king of the Elysian Isles to rule over the shades of the Heroes.

Translation of Light: if planet A is in aspect to planet B, and planet B is in aspect to planet C, then planet A may also be in aspect to planet C even if the orb between A and C is too wide. This is because their mutual aspect to planet B strengthens the aspect between A and C. This effect is particularly noticeable in harmonic syndromes of more than three planets.

Trine: the 120° aspect; one third of the circle, denoting harmony, ease, gifts, stability and creativity; orb 6.5° - 7.5°. Planets in trine are usually (but not necessarily) in the same element. Not conducive to change like the square. To see what a "Trine" looks like in a Natal Chart, Click here!

Tropical: referring to the northerly or southerly turning of the Sun twice a year at the solstices. This marks the seasonal cycle of light and dark on the Earth bringing about the 12 signs. Tropical and sidereal astrologers differ in that the former believe the signs to be 12 equal divisions of the interval between successive vernal equinoxes, and that these 12 stages in the Earth’s light and dark cycle, not the constellations from which they derived their names, are interpretively significant. Sidereal astrologers believe that it is the more fixed, non-precessing constellations that are interpretively significant.

T-Square: an opposition with a third planet square to both ends. Although similar in energy to the Grand Cross, this structure is said to lack its balance, and therefore to focus one’s attention on the "missing leg." A heavy transiting planet filling in the open end often initiates a crisis. To see what a "T-Square" looks like in a Natal Chart, Click here!

Vernal Equinox: the point on the ecliptic at which the Sun is in the plane of the Earth’s equator and day and night are of equal length all over the Earth. The Vernal Equinox defines 0° of the sign Aries, or the beginning of the astrological cycle.

Vertical Circle: a plane perpendicular to the local horizon and passing through the center of the Earth. The "Meridian" is a vertical circle passing through the north and south points on the horizon; whereas the "Prime Vertical" is a vertical circle that passes through the east and west points on the horizon.

Water: one of the four elements (earth, air, fire and water) by which the signs and the houses are categorized. In general, the element of water represents emotion, responsiveness, instability and change. For its application in the signs and houses, see below. To read more about the water element in a Natal Chart, Click here!

Water sign: The responsive, unstable, fertile and flexible element, as exemplified by the water signs Cancer, Scorpio and Pisces. A liquid is that state of matter - the counterpart of the astrological element water - in which the average vibrational energy of the constituent particles exceeds their bonding energy. See "plasma" for an explanation of temperature, absolute zero, and the four states of matter.

Yod: see "Finger of God": A triangular aspect structure: one planet at the vertex in quincunx to two others in sextile. The whole structure points to the planet at the apex: a special task in life beneficial to one’s evolution; thought to be a fateful, constant, and relatively unchanging condition. To see what a "Yod" looks like in a Natal Chart, Click here!

Zodiac: (from the Latin, "band of animals"); those particular constellations, only 12 in number, through which the Sun, Moon and all the planets appear (as seen from the Earth) to move year after year. The planets move only through these 12 constellations due to their orbits all being contained in an infinitely large flat surface called the plane of the ecliptic. This in turn is thought to result from the planets all having condensed from the gaseous equatorial plane of a protostar billions of years ago, the center of which is now the Sun.

**This web site's goal is to provide you with information that may be useful in attaining optimal health. Nothing in it is meant as a prescription or as medical advice. You should check with your physician before implementing any changes in your exercise or lifestyle habits, especially if you have physical problems or are taking medications of any kind.